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Commit 4a9f3a7c authored by Roy Franz's avatar Roy Franz Committed by Matt Fleming
Browse files

efi: Generalize relocate_kernel() for use by other architectures. 



Rename relocate_kernel() to efi_relocate_kernel(), and take
parameters rather than x86 specific structure.  Add max_addr
argument as for ARM we have some address constraints that we
need to enforce when relocating the kernel.  Add alloc_size
parameter for use by ARM64 which uses an uncompressed kernel,
and needs to allocate space for BSS.

Signed-off-by: default avatarRoy Franz <roy.franz@linaro.org>
Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
parent c6866d72

arch/x86/boot/compressed/eboot.c

+8 −2
Original line number Diff line number Diff line
@@ -733,10 +733,16 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table, 
	 * address, relocate it.

	 */

	if (hdr->pref_address != hdr->code32_start) {

		status = relocate_kernel(hdr);



		unsigned long bzimage_addr = hdr->code32_start;

		status = efi_relocate_kernel(sys_table, &bzimage_addr,

					     hdr->init_size, hdr->init_size,

					     hdr->pref_address,

					     hdr->kernel_alignment);

		if (status != EFI_SUCCESS)

			goto fail;



		hdr->pref_address = hdr->code32_start;

		hdr->code32_start = bzimage_addr;

	}



	status = exit_boot(boot_params, handle);

drivers/firmware/efi/efi-stub-helper.c

+55 −21
Original line number Diff line number Diff line
@@ -485,38 +485,72 @@ fail: 


	return status;

}



static efi_status_t relocate_kernel(struct setup_header *hdr)

/*

 * Relocate a kernel image, either compressed or uncompressed.

 * In the ARM64 case, all kernel images are currently

 * uncompressed, and as such when we relocate it we need to

 * allocate additional space for the BSS segment. Any low

 * memory that this function should avoid needs to be

 * unavailable in the EFI memory map, as if the preferred

 * address is not available the lowest available address will

 * be used.

 */

static efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,

					unsigned long *image_addr,

					unsigned long image_size,

					unsigned long alloc_size,

					unsigned long preferred_addr,

					unsigned long alignment)

{

	unsigned long start, nr_pages;

	unsigned long cur_image_addr;

	unsigned long new_addr = 0;

	efi_status_t status;

	unsigned long nr_pages;

	efi_physical_addr_t efi_addr = preferred_addr;



	if (!image_addr || !image_size || !alloc_size)

		return EFI_INVALID_PARAMETER;

	if (alloc_size < image_size)

		return EFI_INVALID_PARAMETER;



	cur_image_addr = *image_addr;



	/*

	 * The EFI firmware loader could have placed the kernel image

	 * anywhere in memory, but the kernel has various restrictions

	 * on the max physical address it can run at. Attempt to move

	 * the kernel to boot_params.pref_address, or as low as

	 * possible.

	 * anywhere in memory, but the kernel has restrictions on the

	 * max physical address it can run at.  Some architectures

	 * also have a prefered address, so first try to relocate

	 * to the preferred address.  If that fails, allocate as low

	 * as possible while respecting the required alignment.

	 */

	start = hdr->pref_address;

	nr_pages = round_up(hdr->init_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;



	status = efi_call_phys4(sys_table->boottime->allocate_pages,

	nr_pages = round_up(alloc_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;

	status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,

				EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,

				nr_pages, &start);

				nr_pages, &efi_addr);

	new_addr = efi_addr;

	/*

	 * If preferred address allocation failed allocate as low as

	 * possible.

	 */

	if (status != EFI_SUCCESS) {

		status = efi_low_alloc(sys_table, hdr->init_size,

				   hdr->kernel_alignment, &start);

		if (status != EFI_SUCCESS)

			efi_printk(sys_table, "Failed to alloc mem for kernel\n");

		status = efi_low_alloc(sys_table_arg, alloc_size, alignment,

				       &new_addr);

	}

	if (status != EFI_SUCCESS) {

		efi_printk(sys_table_arg, "ERROR: Failed to allocate usable memory for kernel.\n");

		return status;

	}



	if (status == EFI_SUCCESS)

		memcpy((void *)start, (void *)(unsigned long)hdr->code32_start,

		       hdr->init_size);

	/*

	 * We know source/dest won't overlap since both memory ranges

	 * have been allocated by UEFI, so we can safely use memcpy.

	 */

	memcpy((void *)new_addr, (void *)cur_image_addr, image_size);

	/* Zero any extra space we may have allocated for BSS. */

	memset((void *)(new_addr + image_size), alloc_size - image_size, 0);



	hdr->pref_address = hdr->code32_start;

	hdr->code32_start = (__u32)start;

	/* Return the new address of the relocated image. */

	*image_addr = new_addr;



	return status;

}